NASA's InSight Lander Detects First Likely 'Marsquake'

The seismic signal was first detected by the lander's Seismic Experiment for Interior Structure instrument on April 6. It was the lander's 128 day on Mars, or sol. Scientists are still examining the data, but they believe the signal originated from within the planet, as opposed to anything that could have come above the surface, like wind.

"InSight's first readings carry on the science that began with NASA's Apollo missions," said InSight Principal Investigator Bruce Banerdt of NASA's JPL. "We've been collecting background noise up until now, but this first event officially kicks off a new field: Martian seismology!"

The seismic event was too small to provide much data on the Martian interior, one of InSight's main missions on the Red Planet. Because the Martian surface doesn't have tectonic plates like we do here on Earth, the Martian surface is extremely 'quiet', which allows InSight's seismometer to pick up even the faintest rumbles from below the surface. A similar event on Earth would likely go unnoticed thanks to the dozens of tiny quakes that happen every day.

The seismometer carried by InSight is similar to those installed by NASA's Apollo astronauts on the moon. Those five seismometers measured thousands of 'moonquakes' while they were active between 1969 and 1977. Because the speed of seismic waves can change or be reflected, scientists can use them to 'map' the moon's interior and gain clues about its formation.

"The Martian Sol 128 event is exciting because its size and longer duration fit the profile of moonquakes detected on the lunar surface during the Apollo missions,” said Lori Glaze, Planetary Science Division director at NASA headquarters.

NASA currently has plans to return astronauts to the moon by 2024, in hopes of laying a foundation for longer manned expeditions to Mars.